Syðradalur is the southernmost of the 4 villages on the island of Kalsoy.
Syðradalur was founded in 1812 by former inhabitants of the village Blankaskáli on the east side of the island.
They moved from their old village because a landslide devastated it.
Syðradalur is said to have been inhabited in the 17th century as well. Why it later was depopulated is unknown.
Syðradalur is connected to the other villages on the island through 4 tunnels. These gave the island the nickname
‘the recorder’ after the flute of that name.
On Streymoy there is another village called Syðradalur (the word Syðradalur means South-valley).